DelAVars deleting wrong variable

[TravisE]

I did some searching but couldn't find any mention of this.
On version 7820; reproducible in a freshly reset PC simulator instance, all default settings, the following command sequence entered directly on the home screen:

Code:

AVars("RADMIN"):=13                                   13
AVars("RADMAX"):=39                                   39
AVars("REVMAX"):=1555                               1555
AVars("LINPOS"):=0                                     0
AVars("TAPENAME"):="TEST"                         "TEST"
DelAVars("TAPENAME")                                   1
AVars
              {"RADMIN", "RADMAX", "LINPOS", "TAPENAME"}

Can someone explain this?